JPH0462108B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an image processing apparatus having a function of performing edge processing when cutting out a desired area.

<Prior Art> As one of the image processing techniques, there is a method of cutting out a certain area in an original image and changing the color of that part.
In this case, the problem is the processing of the edge portion of the cutout area. For example, FIG. 9a shows an enlarged view of the contents of the image memory. If we make the diagonal lines red and the dotted areas blue, the thick edges will stand out and give an unnatural impression. As a technique to avoid this problem, there is a method of replacing the density values of pixels around the edge with the average value of the density values of surrounding pixels. For example, if the average value of the top, bottom, left, and right is taken for each density value within a rectangle as shown in FIG. 9b,
As shown in Figure c, the edge portion becomes an intermediate value between the data in the two areas, and the edge becomes less noticeable.

<Problems to be Solved by the Invention> However, the problem with this method is that the original data is lost because the data of pixels in the edge portion is changed. Therefore, it is unsuitable for a system in which the original color and the changed color are frequently compared, such as in a color change simulation.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to make the unnaturalness of edges, which is a problem when changing the color of a cutout region cut out from an image, less noticeable without losing the original data of the edge portion.

<Means for Solving the Problems> In order to achieve the above object, the image processing device of the first invention uses density information of each pixel constituting an image;
A dual-purpose memory for storing pixels of a clipped region to be clipped with this density information changed or edge information for determining pixels corresponding to edges of the clipped region, and output information of the dual-purpose memory are introduced, and the density information a look-up table memory for changing and outputting density information of pixels corresponding to a cut-out area to be changed and pixels corresponding to edges thereof; and a display means for displaying an image based on the output information of the look-up table memory. , a writing means for writing edge information into the dual-purpose memory, and based on the density information and edge information, the density information of the pixel of the edge represents an intermediate color between the color of the cropped area after color conversion and the color of the original image. The present invention is characterized in that it includes a lookup table setting means for setting the contents of the lookup table memory as shown in FIG.

The image processing device of the second invention also includes an image memory that stores the density of each pixel constituting the image, and a pixel of a cutout area whose density information is changed and is cut out or a pixel corresponding to an edge of the cutout area. an edge memory that stores edge information for determining the
The output information of both the image memory and the edge memory is introduced, and the lookup table memory changes and outputs the density information of the pixel corresponding to the cutout area whose density information is to be changed and the pixel which corresponds to its edge. A display means for displaying an image based on the output information of the up table memory, a writing means for writing edge information into the edge memory, and a display means for displaying an image based on the output information of the up table memory; Lookup table setting means for setting the contents of the lookup table memory so as to represent an intermediate color between the color after color conversion and the color of the original image,
The feature is that the color of the cutout area is changed so that the edges are not noticeable.

<Function> Density information and edge information are retained in the dual-purpose memory or image memory and edge memory, and in the lookup table memory, the density information of the pixel corresponding to the edge of the cutout area is divided into the color after color change and the color before change. The lookup table setting means changes the color so that the color is intermediate between the two.

Therefore, the edge portion is displayed inconspicuously without changing the original data of the edge portion.

<Example> Hereinafter, the present invention will be explained in detail using specific examples. Figure 1 shows full-color images of R (Red) and G.
2 is a block diagram of an image processing device that separates the color into three components of (green) and B (blue) and stores them. FIG. This image processing apparatus includes a dual-purpose memory 15 of 8 bits each for RGB, and this dual-purpose memory 15 stores density information constituting an image and edge information for determining a cutout region or its edge, depending on the case. The output of the dual-purpose memory 15 is connected to the address of a lookup table memory 16, and the output of the lookup table memory 16 is connected to a D/A converter 18 via a gate circuit 17.

The lookup table memory 16 is bus 1.
4. Accessed by microprocessor 13 through gate 20. The above microprocessor 13
includes a lookup table setting means for calculating and rewriting density information in the lookup table memory 16, which will be described later.

Further, the output (video analog signal) of the D/A converter 18 is sent to a display 19, where an image is displayed. The dual-purpose memory 15 and main memory 12 are accessed by the microprocessor 13 via the bus 14. Coordinate input means 2
1 is accessed by the microprocessor 13 through the bus 14, and allows input of specific coordinates on the image.

Next, the processing of this device will be explained. first,
Images are input into the dual-purpose memory 15 using means such as a scanner or a TV camera. At this stage, the dual-purpose memory 15 stores 8 bits of each RGB information per dot. Next, as an example, the upper 6 bits of the dual-purpose memory 15 are used for image information, that is, density information, and the lower 2 bits are used for edge information. FIG. 2 shows the dual-purpose memory set in this way. How many bits are used for image information and how many bits are used for edge information may be changed depending on the content of the input image information. To perform the settings as described above, the K component (K=r,
The information stored in g, b) is concentration information i _K (0≦i _K
<2 ⁶ ) and edge information e (0≦e<2 ² ),
The output x _K of the dual-purpose memory 15 becomes x _K =2 ² ×i _K +e.

Next, a method of performing edge processing using edge information will be explained. First, edge information is set as follows using the writing means included in the microprocessor 13. The background area is set to 0, the cutout target area is set to 3, and among the areas that require edge processing, an area close to the cutout target area is set to 2, and an area far from the cutout target area is set to 1. FIG. 3 shows an example of writing edge information.
The shaded area is the edge processing area.

Furthermore, the following methods can be considered as methods for writing edge information.

A method for writing edge information 3 into the region to be cut out has already been invented by the present inventors. It is possible to use a method of cutting out using a threshold value regarding color density information.

A possible method for writing edge information 0 in the background area is to write 0 in advance to all edge information before writing edge information.

The following methods can be considered for writing edge information 1 and 2 in the edge processing area.

(1) First, a method can be considered in which a brush-like figure that moves according to the coordinate values input by the coordinate means 21 is displayed on the screen, and edge information 1 or 2 is written at the display position of this figure. Here, the size of the figure may be selected from several types.

Also, as shown in Figure 4a, set a brush means to write edge information 2 in the center and edge information 1 around it, and use this brush means to set edge information 1 and 2 at the same time. There are other possible methods. When using this brush means, the edge information value to be written is compared with the edge information that has already been written at that position, and if it is larger, writing is performed. For example, if edge information is given as shown in Fig. 4b, and if you move the brush in Fig. 4a as shown by the arrow, an edge will appear in the background area as shown in Fig. 4c. Information is written. Now, this brush means has a function of writing edge information in the background area, but a method of writing edge information while scraping the cut out area can also be realized as follows. For example, as shown in Figure 5a, a brush means is set to write edge information 0 in the center, edge information 1 around it, and edge information 2 around it, and the information to be written is already at that position. The edge information is compared with the edge information that has been written, and if it is smaller than the edge information, writing is performed.

As a result, in addition to providing edge information as shown in FIG. 5b, for example, as shown by the arrow,
When the brush means shown in FIG. 5a is moved, edge information is written in the cut out area as shown in FIG. 5c.

(2) In the previous example, a method was shown in which edge information was written interactively near the coordinates input by the coordinate input means 21, but a method that does not use a graphic such as a brush means may also be considered.

For example, the method shown in FIG. 6a is an example in which edges of a region cut out in advance are tracked and edge information 2 is written around them. If you use the same method and further write edge information 1 around it,
The result will be as shown in Figure 6b. As a method for tracking edges, a method used for analyzing binary images, such as a method using a 3×3 mask, can be used. Naturally, the number of layers of edge information to be added to the surrounding area can be selected in various ways depending on the situation. Another possible method is to add edge information only to a part of the periphery of the cut out area. For example, there is a method in which a rectangle is input as shown in FIG. 6c, and the above processing is performed only within this rectangle. This method has the advantage that edge information is not added to areas where edges should be left intact, and edge information can be written only to areas where edges are desired to be smoothed. Furthermore, in the above example, the edge information is written from the periphery of the cut out region outwards, but it is of course possible to write it inward.

Several methods for writing edge information have been described above, but the important point is that edge information values that are different from those of the cut out area or background are written in the portion where edge processing is to be performed.

Next, in order to change the color so that the edges are not noticeable using the edge information set as above, the lookup table memory 16 should be calculated and set as follows using the lookup table setting means. good. Here, i _K is the output of the density information of the K component of the color, and the output x _K of the density/edge dual-purpose memory and the edge information e have a relationship of x _K =2 ² ×i _K +e. f _K
(x _K is the output of the lookup table memory 16, and [ ] is a Gaussian symbol.

f _K (x _K = [e×F _K (i _K ) + (3-e
)×I _K (i _K )/3]
(e=0, 1, 2, 3) The meaning of this formula is that it outputs a value that is a mixture of the values of the functions f _K (i _K ) and I _K (i _K ) according to the value of edge information e. be. In other words, if edge information e is 0
f _K (x _K )=I _K (i _K ), and when edge information e is 3
f _K (x _K )=F _K (i _K ), but if e is 1 or 2, f _K (i _K ) will be an intermediate value between the two. From the above, if F _K (i _K ) is set as a function that converts the density information of the image and outputs it, and I _K (i _K ) is set as a function that outputs the density information of the image as it is, then the cropping area will be (e=3) is a color-changed image by F _K (i _K ),
In the background area (e=0), the original image based on I _K (i _K ) is displayed. Furthermore, if there is an edge processing area (e=1, 2) between the two areas, an intermediate color between the color-changed image and the original image is displayed in that area, so that the edges are not noticeable.

FIGS. 7a, b, and c show examples of the R, G, and B components of the lookup table set as described above, respectively. Here, the solid line represents a color conversion function F _K that emphasizes red and reduces green and blue, the dotted line represents a function I _K that displays the original image, and the dashed line represents an intermediate function. The black circles are the values actually set in the lookup table memory. The horizontal axis is x _K and the vertical axis is f _K
(x _K ).

In this embodiment, the amount of edge information is set to 2 bits, but the amount of information may be increased.

In addition, in this embodiment, only one type of color change can be made at the same time, but by setting label information to specific bits in addition to density information and edge information, it is also possible to change multiple colors at the same time. It is possible. The present inventors have already invented an image processing device that performs multiple color changes using a dual-purpose memory for shading information and label information, but the present invention combines this method to perform multiple color changes with an eye to the edges. It is also possible to do it without.

In addition, in this embodiment, the edge information is stored in the shared memory 1.
Although an example in which edge information is stored in 5 is shown, as shown in FIG. 8, an edge memory 26 exclusively for edge information may be provided separately. The edge information needs to be the same for each RGB color, so it only needs to be for one screen, and its output is connected to the input of the lookup table memory for each RGB color. The image processing device shown in FIG.
Since it is similar to the figure, the explanation will be omitted.

<Effects of the Invention> According to the present invention, a dual-purpose memory for density information and edge information, or an image memory and an edge memory, a lookup table memory, a writing means for writing edge information, and a Since we have provided a lookup table setting means for setting the contents of the lookup table memory, the density information of the image can be retained without being rewritten, and therefore the cropping process by changing the color can be performed any number of times at very high speed. and edge processing to make the edges less noticeable.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an image processing apparatus according to an embodiment of the present invention, FIG. 2 is a diagram explaining the contents of a dual-purpose memory and a lookup table memory, and FIG. 3 is a diagram showing a figure in which edge information is written. , Figure 4a,
b, c, Fig. 5 a, b, c are explanatory diagrams of the brush means, Fig. 6 a, b, c are diagrams showing figures written with edge information, Fig. 7 a, b, c are lookup tables. FIG. 8 is a block diagram of another embodiment, and FIGS. 9a, b, and c are diagrams showing conventional edge processing. 12... Main memory, 13... Microprocessor, 14... Bus, 15... Dual-purpose memory, 16
... Lookup table memory, 17 ... Gate circuit, 18 ... D/A converter, 19 ... Display, 20 ... Gate circuit for reading and writing lookup table, 21 ... Coordinate input means, 25 ... Image memory , 26...Edge Memory.

Claims (1)

[Scope of Claims] 1. Stores density information of each pixel constituting an image, and edge information for determining a pixel of a cutout area whose density information is changed and is cut out or a pixel corresponding to an edge of the cutout area. a look-up table memory into which the output information of the dual-purpose memory is introduced, and which changes and outputs the density information of pixels corresponding to the cutout area whose density information is to be changed and pixels corresponding to the edges thereof; a display means for displaying an image based on the output information of the lookup table memory; a writing means for writing edge information into the dual-purpose memory; A look-up table setting means is provided for setting the contents of the look-up table memory so as to represent an intermediate color between the color of the region after color conversion and the color of the original image, so that the color change of the cut-out region is made so that edges are not noticeable. An image processing device characterized in that it performs the following operations. 2. The image processing apparatus according to claim 1, wherein the writing means writes edge information having different values from the center of the input area toward the periphery. 3. An image memory that stores density information of each pixel constituting an image, and an edge memory that stores edge information that determines pixels of a cutout area whose density information is changed and is cut out or pixels that correspond to edges of the cutout area. , a lookup table memory into which output information from both the image memory and the edge memory is introduced, and which changes and outputs the density information of pixels corresponding to the cutout area whose density information is to be changed and pixels corresponding to the edges thereof; a display means for displaying an image based on output information of the lookup table memory; a writing means for writing edge information into the edge memory; and a display means for writing edge information into the edge memory; and a lookup table setting means for setting the contents of the lookup table memory so as to represent an intermediate color between the color after color conversion and the color of the original image. An image processing device characterized in that the image processing device performs the following operations. 4. The image processing apparatus according to claim 3, wherein the writing means writes edge information having different values from the center of the input area toward the periphery.